1. Field of the Invention
The present invention relates to a composition comprising an isothiazolone compound mixed with a branched cyclodextrine, which is stable to water.
2. Description of the Prior Art
With increasing demand for industrial water, use of recycle water system has been extensively carried on, but in such use, restraint and control of proliferation of microbe are becoming important problems. And with diversification of industrial materials besides such industrial water, damage caused by proliferation of microbe and that by growth of mold cover a wide range. Especially, it is of urgent necessity to deal with a slime problem of fungi, bacteria, yeasts, algae, etc. which are parasitic on drainage used in a process of paper manufacturing, industrial cooling water, lubricating oil for metal processing, aqueous emulsion, or paper, timber, plywood, paste, pulp, fiber, etc., or microbe damage and so on.
Recently, isothiazolone compounds have been given attention as industrial biocides for the purpose of preventing microbe from generating or removing it, and being found that they have a wide range of application and excellent effects.
Generally speaking, it is desirable for industrial biocides of this kind to be solutions, but it has been known that these isothiazolone compounds are easily decomposed by reducing nucleophilic bodies and so on. Therefore, they are very unstable and have remarkable quality changes for aqueous solution preparations, while an increased proportion of an organic solvent in the solution component brings about, for example, a problem on storage with regard to the Fire Service Act, leading to the difficulty in providing stable products as solutions.
Then, aqueous solution preparations containing an isothiazolone compound which are stable as products for a long period are required. For example, in Japanese Patent Laid-Open Publication Nos. 78102/84, 78103/84, 78104/84, 78109/84, 35603/88 and 50322/88, it was proposed to stabilize an isothiazolone compound in an aqueous solution with metal salt (MXn: M is a metal selected from among magnesium, calcium, potassium, copper, iron, zinc, manganese, silver, cobalt, nickel and so on, X is an anion selected from among chloride, bromide, iodide, sulfate, nitrate, nitrite, acetate, perchlorate, bisulfate, bicarbonate, oxalate, carbonate, phosphate and so on, n is an integer to be fitted for the valence of anion and cation) in order to stabilize an aqueous solution preparation. However, metal salt containing metal ions such as calcium and magnesium is not desirable since it causes the occurrence of turbidity or precipitate in the subject. Especially in the case that it is added to anionic macromolecular disperse system, co-existing metal stabilizers make the anionic macromolecular disperse system unstable, resulting in the occurrence of cohesion, a fatal problem, so that the aqueous solution preparations disclosed in the above publications are not sufficiently desirable as products. And conventional metal salt besides the above does not have a stabilization effect sufficient as a stabilizer or have the same defect as magnesium salt and so on, so that it also cannot provide a desirable product. Besides, alkali salt of iodic acid or that of bromic acid were proposed in Japanese Patent Laid-Open Publication No. 286815/93, but it is very difficult to use these stabilizers, since these belong to class 1 dangerous goods and have a danger of explosion. A composition whose skin stimulativity andmucous membrane stimulativity were remarkably reduced by making a clathrate compound with addition of .alpha., .beta. and .gamma. cyclodextrine was proposed in Japanese Patent Laid-Open Publication No. 247011/93, but it has been used only as a dust or suspension.